The Armstrong 811 Cast Iron Inverted Bucket Steam Trap is engineered for reliable condensate drainage in low-to-medium pressure steam systems. Built with a cast iron body rated to 250 psig at 450°F (17 barg at 232°C), the Model 811 handles capacities up to 1,050 lb/hr (476 kg/hr) with a maximum operating pressure of 250 psig (17 barg). This workhorse trap is designed for horizontal installation and serves a broad range of industrial steam applications.
The inverted bucket design uses a free-floating stainless steel mechanism with no fixed pivots or linkages, ensuring long service life with minimal maintenance. As steam enters, the bucket rises to close the valve; when condensate accumulates, the bucket sinks to open the valve and discharge condensate. This simple operating principle provides reliable, continuous air venting at steam temperature for efficient system startup and operation.
Key Features
- Free-floating stainless steel inverted bucket mechanism — no fixed pivots to wear
- Continuous air venting at steam temperature for efficient system startup
- Cast iron body rated to 250 psig at 450°F for durability in industrial steam systems
- Discharge orifice at top of trap — dirt purged automatically when bucket sinks
- Water seal prevents live steam loss
- Field-repairable internals — repair without removing from the line
- Resistant to water hammer
Applications
Ideal for drip, tracer, and process applications in commercial and industrial steam systems where reliable condensate removal and energy efficiency are priorities. Available with screwed NPT and BSPT connections in 1/2″ (15 mm), 3/4″ (20 mm), and 1″ (25 mm) sizes.
